The present invention relates to an apparatus associated with a fuel injection pump for compensating a quantity of fuel injection and, more particularly, to a fuel injection compensator of the type which uses a diaphragm for controlling a control sleeve of the pump in response to a variation in atmospheric pressure or in boost pressure.
Where an internal combustion engine designed for use at ordinary low altitudes is operated at high altitudes as during uphill climbing of a motor vehicle, an excessive supply of fuel occurs due to the thin air and this not only deteriorates the fuel economy but causes emission of smoke resulting in environmental pollution. A known apparatus for settling this problem employs a bellows formed of metal, a control pin having a cam section and moved by the control pin, and a follower or sensor pin displaced by the cam section to in turn adjust the position of a control sleeve.
Some of modern motor vehicles are equipped with a turbo mechanism to attain smooth acceleration. An apparatus has been proposed which adjusts the position of the control sleeve as in the apparatus mentioned above by sensing a boost pressure of a supercharger in the turbo mechanism and, when it is intensified, causing a diaphragm to move the control pin and, thereby, the sensor pin through the cam section.
However, mounting both the apparatus using the metal bellows and the apparatus using the diaphragm on a fuel injection pump renders the pump unadvantageously bulky, heavy and quite intricate in construction.